hi think ive mislead you that works if u want to change the spot colours values to rgb. but the colours when printed are different when printed that on screen what i am looking for is the colours printed to rgb so i can put a true jpg online of the product

You don't need to convert anything. A screen will never look like a printout, it's not possible due to physics. Making a picture of a printout of a picture is even farther from truth of the original photo.

The best thing to do in this situation is to load the (colour-faulty) jpg into PhotoPaint or something similar, then click on 'adjust' in the menu bar (top of screen). On the drop down menu that appears, select: 'hue/saturation/lightness'. The slider controlling 'hue' can then be moved to the left or right with the erroneous (or master) colour/s selected, and this will alter its hue. Move the slider in small increments, or the colours will change entirely! Save the new image to file.